Three cylinder compressor



962 R. J. HACKBAR.T ETAL 3,065,902

THREE CYLINDER COMPRESSOR Original Filed June 26, 1958 2 Sheets-Sheet 1 FIG 2 INVENIORS REUBEN J. HACKBART EMIL T. NEUBAUER imavm ATTORNEYS Nov. 27, 1962 R. J. HACKBART ET AL 3,065,902-

THREE CYLINDER COMPRESSOR Orl glna.1 Filed June 26. 1958 2 Sheets-Sheet 2 INVENTOR5 REUBEN J. HACKBART EMIL T. NEUBAUER /wvm ATTORNEYS United States Patent Ofiice 3,065,902 Patented Nov. 27, 1962 3,065,902- THREE CYLINDER COMPRESSOR Reuben J2 Hackbart, La Crosse, Wis., and'Emil'T. Neubauensidney, Ohio; assignors to The Trane'Company,

La (Crosse; Wis.', 21 corporation-of-Wisconsin Continuation of applicationSer. No.-744,795, June 26,

1958. This application Feb. 8, 1960, Ser. No. 7,212

2 Claims.- (Cl. 230-187) This application is a continuation of applicants application Serial No. 744,795 filed June 26, 195 8, now abandoned.

This invention relates to compressors and more specifically to a new and improved three. cylinder compressor with two crank throws.

Previous to this invention, refrigeration compressors of three cylinders had cylinders which were either spaced radially around the periphery of the compressor with 120 between cylinders or were spaced around the upper half of the compressor with the cylinders 60 apart. Both of the above compressor designs incorporated a single throw crankshaft with all the connecting rods connected to a single throw. Both of the above compressor designs have disadvantages which impair the efliciency of the compressor. The three cylinder compressor with 120 between cylinders has a serious slugging problem. It is obvious that refrigerant and oil Will collect in the lower cylinder and that on the compression stroke liquid refrigerant and oil will slug against the cylinder head causing damage to the compressor. The above mentioned three cylinder compressor with 60 between cylinders was designed to overcome this slugging problem, but since a single crankshaft with a single throw with all the cylinders connected to the throw is used, the torque requirements are high and the suction gas impulses are unevenly spaced causing a decrease in compressor efficiency and a higher noise level which is undesirable.

An object of the invention is to provide a three cylinder compressor which is not prone to slug and has lower torque requirements thereby improving the efficiency of the compressor and at the same time providing quieter operation.

Another object of the invention is to provide a three cylinder compressor with a two throw crankshaft which is efficient and quiet in operation.

A third object of the invention is to provide a three cylinder compressor which is inexpensive to manufacture and easy to assemble and repair.

Another object of the invention is to provide a three cylinder compressor with a two throw crankshaft which spreads the suction stroke through an angle of 360 to lower the torque requirements and greatly lessen the possibility of slugging.

Other objects and advantages of the invention will be clearly apparent as the specification proceeds to describe the invention with reference to the accompanying drawings in which:

FIG. 1 is a roll out view of the cylinders of the compressor shown in FIG. 2;

FIG. 2 is a left end elevation view of the compressor shown in FIG. 3;

FIG. 3 is a sectional view taken in line 33 of FIG. 1.

Referring now to FIGS. 1 and 2, there is shown a compressor with cylinders 12, 14, and 16 closed by cylinder heads 18, 20, and 22, spaced around the periphery of circular compressor housing 24 with the axial centerline of cylinder 12 being spaced 60 counterclockwise from the axial centerline of cylinder 14 and the axial centerline of cylinder 16 being spaced 60 clockwise from the axial centerline of cylinder 14. Note 2- that the axialcenterline of cylinder 14 is perpendicular to crankshaft 26.

The centerline.13 ofcylinder 14 is spaced towardsthe suction sideof the compressor a fixed determined distance from the centerline 11 of cylinder 12. The fixed distance between cylinder 1 2 and cylinder 14 is deter mined by manufacturing andspace requirements and is not. part of the. invention.

As statedabove, the axial centerlines of cylinders 12 and 16 are. spaced around the periphery of the compressor. housing 24,.120 from each other. It is obvious that the centerline.15of'cylinder 16 is spaced one connecting rod width towards the discharge side of the compressor 10 from the centerline 11 0f cylinder 12.

As shown in' FIG. 3, crankshaft 26 with two throws 28 and 30 is connected to pistons 32 by means of connecting rods 34. Cylinder 14 is shown in section while cylinders 12 and 16 are not shown but are identical in structure to that of cylinder 14.

In operation, as the piston 32 descends on the suction stroke, gaseous refrigerant is drawn in suction inlet 36, through suction strainers 38, and then through suction valve ports 40 past suction valve 42 into compression chamber 44 which is formed by cylinder liner 46.

As the piston rises on the compression stroke, the gaseous refrigerant is compressed holding suction valve 42 closed and forcing discharge valve 48 in discharge valve cage 50 open thereby discharging the compressed refrigerant into the discharge chamber 52 from where it passes to the discharge outlet 54.

It should be noted that the discharge valve cage 50 is secured in position by helical spring 56 which, if a slug of liquid refrigerant should enter the compression chamber 44, will allow the discharge valve cage to move upwardly thereby allowing the liquid to pass to the discharge outlet 54 without causing damage to the compressor.

The use of the two throw crankshaft in conjunction with the herein disclosed layout provides a compressor which has minimum torque requirements and is not prone to slug resulting in greater efficiency and quieter operation. The torque requirements of our compressor are less since the suction gas impulses are evenly spaced through an angle of 360 by the use of the two throw crankshaft. Obviously, we have provided a three cylinder compressor which has the advantages of a three cylinder radial compressor without the disadvantage of constant slugging by the liquid refrigerant and oil.

Although we have described in detail the preferred embodiment of our invention, we contemplate that many changes may be made Without departing from the scope or spirit of our invention, and we desire to be limited only by the claims.

We claim:

1. A three cylinder refrigeration compressor consisting of a housing, means forming a first cylinder, a second cylinder, and a third cylinder in said housing, means forming a crankcase chamber in said housing, means forming a common suction chamber for said cylinders in said housing, a crankshaft in said crankcase chamber having a first throw and a second throw, said cylinders being located above the axis of said crankshaft with their axial centerlines being angularly displaced from one another, said axial centerline of said first cylinder being between the axial centerlines of said second and third cylinders, pistons slidably mounted in each of said cylinders, three connecting rods connected to said crankshaft, one of said connecting rods being connected to said first throw at one end and connected to said piston in said first cylinder, and the remaining two connecting rods being connected at one end to said second throw and being respectively connected to said pistons in said second and third cylinders whereby slugging by the compressor will be eliminated.

2. A three cylinder refrigeration compressor consisting of a housing, means forming a first cylinder, a second cylinder and a third cylinder in said housing, means forming a crankcase chamber in said housing, means forming a common suction chamber for said cylinders in said housing, a crankshaft in said crankcase chamber having a first throw and a second throw, said cylinders being located above the axis of said crankshaft with their axial centerlines being angularly displaced from one another with the axial centerline of said second cylinder being located substantially 60 clockwise of the axial centerline of said first cylinder and the axial centerline of said third cylinder being located substantially 60 counterclockwise of the axial centerline of said first cylinder, pistons slidably mounted in each of said cylinders, three connecting rods connected to said crankshaft,

one of said connecting rods being connected to said first throw at one end and connected to said piston in said first cylinder, and the remaining two connecting rods being connected at one end to said second throw and being respectively connected to said pistons in said second and third cylinders whereby slugging by the compressor will be eliminated and the suction gas impulses are substantially evenly spaced throughout a 360 rotation of said crankshaft to provide minimum torque requirements and quiet operation of said compressor.

References Cited in the file of this patent UNITED STATES PATENTS 

